In a printing field called POD (print on demand), the image forming system configured by the image forming apparatus and the bookbinding apparatus creates a book without using a printing plate.
For example, as disclosed in Unexamined Japanese Patent Application Publication No. 2008-80603, many of the bookbinding apparatuses for POD use a gluing apparatus as a device for bookbinding the sheet bundle with a binding process. Since the structure of the gluing apparatus is simple and small, the gluing apparatus is suitable for combining into the image forming apparatus.
In Unexamined Japanese Patent Application Publication No. 2008-80603, a temperature of an adhesive storage section heater, a temperature of an application device heater and a temperature of adhesive are separately detected in an application apparatus that includes the adhesive storage section heater and the application device heater. The above mentioned adhesive storage section heater and the above mentioned application device heater are separately controlled based on the detection temperature. Thus, the temperature of the adhesive in the adhesive storage section becomes even and the adhesive is quickly melted.
In Unexamined Japanese Patent Application Publication No. H10-35138, a warm-up time is shortened and the power consumption is controlled by having different number of heaters for the warm-up time and an application time.
Also as pointed out in Unexamined Japanese Patent Application Publication No. H10-35138, shortening of the wait time, which is from when the adhesive heating device is turned on to when the adhesive is melted and becomes ready to be applied, is a technical object needed to be solved in the bookbinding apparatus using a gluing apparatus.
The wait time is the time from when a heating device for heating the adhesive is turned on to when the temperature of the adhesive rises to the temperature in which the adhesive become applicable, namely, a warm-up time. In Unexamined Japanese Patent Application Publication No. 2008-80603 and Unexamined Japanese Patent Application Publication No. H10-35138, the warm-up time is shortened by using a plurality of heaters as the heating device and controlling the plurality of heaters separately.
However, there is a limitation in such warm-up time shortening device. Thus, the warm-up time cannot be shortened enough.
As described above, in the warm-up, the adhesive is heated until the temperature of the adhesive reaches the application temperature. Therefore, the application temperature is set as a standard of the control. The warm-up completes when the adhesive temperature is detected to have reached the standard temperature.
In such warm-up control, in order to shorten the warm-up time, the speed of raising the temperature needs to be increased. Therefore, there is a need to increase the power of the heater. Thus, an increase in power consumption cannot be avoided.
In Unexamined Japanese Patent Application Publication No. 2008-80603, the plurality of heaters is separately controlled so that the adhesive temperature is uniformly raised and the warm-up time can be shortened. However, in order to shorten the warm-up time, the number of heaters or the power of the heater needs to be increased. Since Unexamined Japanese Patent Application Publication No. H10-35138 is in the similar manner, a heater that is turned on only at the warm-up time is needed. Thus, since there is large power consumption during the warm-up, the maximum power of the apparatus becoming large cannot be avoided.